×
The submission system is temporarily under maintenance. Please send your manuscripts to
Go to Editorial ManagerThis study investigates the vibration behavior of cantilever beams with bolted joints of different lap types (single lap and double lap) under free and forced vibration conditions. The effects of various parameters, including beam configuration, bolt preload, harmonic force magnitude, and force application position, on natural frequency, mode shape, and vibration amplitude are analyzed. Experimental work involved material selection, chemical composition testing, tension tests, beam preparation, and free and forced vibration tests with pre-torque ranging from 6 to 60 N·m and rotational speeds between 300 and 900 RPM. Numerical simulations were performed using the general-purpose finite element software ANSYS 16.1. Results indicate that the natural frequencies of single-lap bolted beams (1 or 2 bolts) are approximately equal to those of intact beams, while double-lap bolted beams exhibit slightly lower natural frequencies than intact beams with the same profile. Increasing bolt preload stabilizes the natural frequency for all beam configurations. For forced vibrations, the amplitude is strongly influenced by the magnitude and position of the applied harmonic force. Validation with experimental results shows good agreement, with a maximum error of approximately 5%.
Dynamic behavior of pipe conveying fluid at different cross section is investigated. Three kinds of supports are used, which are flexible, simply and rigid supports. The type effect of support on vibration characteristics and dynamic specification are studied. Also, the effect of some design parameters such as pipe material and Reynold numbers are investigated. The governing equations of motion for this system are derived using the finite element method which depends on beam theory. A finite element software (ANSYA-11) is presented to find first three eigenvalue (natural frequency) and eigenvector (mode shape) for pipe system in modal analysis. Velocity and pressure distribution are evaluated in a single phase fluid flow. A coupled field fluid-structure analysis was then performed by transferring fluid forces, solid displacements, and velocity across the fluid-structure interface. Finally the effective stresses (Von mises stress) in piping system are predicted in static analysis at various Reynold numbers, pipe material and pipe supports.